While the mere mention of the word statistics may be intimidating for some, every one of us is truly more familiar with them than we think. We hear them in advertisements all the time (for example, “95 percent of dentists surveyed recommend …”). You may have heard someone ask how many miles a vehicle averages per gallon. Understanding statistics is useful far beyond formal data analysis and evaluation. It truly helps us be more aware consumers of knowledge, products, services—everything in everyday life—so that we can make good decisions and evaluate with knowledge.

There are two main types of statistics: descriptive and inferential. The first step in making sense of data is to summarize or describe them. As the name implies, descriptive ...

Get Performance Evaluation: Proven Approaches for Improving Program and Organizational Performance now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.